Medical professionals commonly use radiation emitting medical instruments for medical diagnosis and treatment. More specifically, medical professionals may use radiation emitting medical devices for the treatment of cancer and medical imaging.
Medical imaging creates images of the human body for clinical purposes such as treatment of diseases, diagnosing diseases, and study of the human body. Many different types of medical imaging technology currently exists such as radiography (using x-rays), magnetic resonance imaging (MRI), tomography, ultrasound, and echocardiography. Some of these imaging technologies make use of radiation. While the radiation may be dangerous at high doses, controlled doses by medical imaging technology provides valuable pictures of the human body. These medical images may provide medical professions with a perspective of the body that cannot be seen by the naked eye, like bones structure.
The use of medical imaging is necessary for some medical treatments. Radiology, which is a common form of medical imaging, uses x-rays to produce an image of a part or all of the human body. X-rays, like visible light, are a type of radiation. X-rays have a much smaller wavelength (0.01 to 10 nanometers) and higher photo energies (100 eV to 100 keV) than visible light. The properties of x-rays provide both useful and harmful functions.
Because of the nature of some types of radiation, it can be harmful to cells in the human body. More specifically, radiation that carries enough energy to separate an electron from an atom or molecule is called ionizing radiation. Types of ionizing radiation include alpha rays, beta rays, gamma rays, and x-rays. If an ionizing ray interacts with a human cell, the cell may become ionized, which in turn damages or mutates the cell. On a more macro scale, extremely high doses of radiation can cause radiation burns and death. Some doses of radiation may cause cancer after exposure. Because of the risks for harm, unprotected exposure to ionizing radiation should be prevented.
Medical equipment that emits radiation may also be used for treatment of disease. Radiation therapy uses ionizing radiation for the treatment of cancer. By targeting ionizing radiation rays at cancer cells, tumors may be prevented from growing and in some cases may be reduced in size. Radiation therapy is useful in this situation because the dangerous rays are being targeted at harmful cancer cells. When applying radiation therapy, a radiologist must carefully select a location and a dosage of the applied radiation. Usually the location and dosage are electronically controlled for a more exact treatment of cancer. If radiation is not applied to the correct area of the body, the radiation may harm healthy cells instead of the cancerous cells.
While doctors control the amount of radiation exposure that a patient is subject to during a simple x-ray or an computed tomography (CT) scan, the radiation may still be dangerous. Doctors take affirmative steps to protect patients receiving an x-ray or CT scan, such as providing lead shielding, but protection from radiation is equally important for those who are not shielded, such as a radiologist performing the scan, nurses assisting in the scan, or family members of the patient providing moral support. So, measures should be taken to protect people other than the patient as well.
Generally, all people other than the patient should be a safe distance away from the radiation equipment and usually are outside of the room housing the radiation equipment. However, in some cases, a family member, who may be unshielded, may remain in the scanning room during the scan. Alternatively, a doctor or nurse may still be explaining the radiation procedure to the patient when a radiologist accidentally starts the scan. Many situations exist where an unshielded person other than the patient may remain in the treatment room and is exposed to dangerous radiation. These situations should be avoided at all costs because of the possibility of inducing cancer or other harm.
Currently, the only protective measure against unprotected radiation exposure in a medical treatment room is the diligence of the operator of the radiation equipment. While generally effective, the risk of an unprotected radiation exposure is too high to leave in the hands of just the operator. The operator has a lot of responsibility including checking that the radiation equipment is properly positioned, answering patient questions, providing radiation shielding (or other protective measures) to the patient, and also confirming that no unprotected people are proximate to the scanning equipment. With all these responsibilities, an operator may forget to do a headcount before activating the radiation equipment. Thus, to prevent unprotected exposure, the field of medicine needs a safety system to assure that only a protected patient is subject to radiation from the radiation equipment.